Astragaloside IV reduces the hypoxia-induced injury in PC-12 cells by inhibiting expression of miR-124.

Background Astragalus membranaceus has been clinically used in cerebral ischemia treatment in China and its main component, Astragaloside IV (Ast IV) shows anti-hypoxia activity, but the underlying mechanism has not been clearly clarified. This study was aimed to investigate the effects of Ast IV on hypoxia-induced injury in PC-12 cells as well as the underlying mechanism. Methods Relative miR-124 expression was detected by qRT-PCR. Hic-5 expression was analyzed by qRT-PCR and Western blot. To alter miR-124 and Hic-5 expressions, cells were respectively transfected with miR-124 mimic and pEX-Hic-5. Cell proliferation and apoptosis were measured by BrdU assay and Annexin V-fluorescein isothiocynate (FITC)/propidium iodide (PI) double staining method, respectively. Besides, apoptotic proteins and cell proliferation-associated factors were analyzed by Western blot. Results Ast IV alleviated hypoxia-induced injury in PC-12 cells by decreasing apoptosis ( P  <  0.01). Ast IV inhibited up-regulation of miR-124 induced by hypoxia ( P  <  0.01). miR-124 mimic impaired the anti-apoptotic effect of Ast IV on PC-12 cells ( P  <  0.01). Hic-5 expression was significantly down-regulated in miR-124 overexpressed cells ( P  <  0.001) and Hic-5 overexpression activated Sp1/Survivin signaling pathway ( P  <  0.001). Conclusion Ast IV could ameliorate hypoxia-induced injury in PC-12 cells by decreasing miR-124 expression and then up-regulating Hic-5 expression. [ABSTRACT FROM AUTHOR]